I have researched some of the bel and escort radar detectors and am trying to understand which has the best radar receiver. In the manuals it tells you what type of oscillator it has but it doesn't make sense to me. The bel vectors all have VTO, the X50 has VTO, the 9500 has Varactor Tuned VCO (is this the same as VTO?) the rx65 and earlier model escorts have GaAs FET VCO. Is one of these better that the other?